Boring head

ABSTRACT

A boring head has a boring head body having a shank on the upper part thereof, and bit mounting means is slidably fitted into a transverse channel formed on the underside of the body. A bit is secured to the bit mounting means. In one embodiment a bolt is loosely fitted into a transverse hole formed through the mounting means, one end thereof being loosely fitted through a hole formed on one side of the concave channel of the body. The other end of the bolt is screwed into a threaded hole formed on the other side of said concave channel. Wedge members are provided in concavities above the transverse channel which are moved by bolts therethrough to wedge the mounting means downwardly while it is loosely held by the bolt through the transverse hole, after which the bolt s tightened to secure the mounting means. In a second embodiment the mounting means has a helical rack gear thereon meshing with a sliding member in a transverse hole above the transverse channel, and a bolt threaded through the sliding member moves the sliding member when the bolt is rotated, thereby moving the mounting means.

United States Patent [191 Mizoguchi [451 May 1,1973

[ BORING HEAD Sutemaru Mizoguchi, No. 1738, Ohaza, Kitahara, lkoma-cho,Ikoma gun, Nara, Japan [76] Inventor:

Primary ExaminerFrancis S. Husar Atl0rneyWenderoth, Lind & Ponack [57]ABSTRACT A boring head has a boring head body having a shank on theupper part thereof, and bit mounting means is slidably fitted into atransverse channel formed on the underside of the body. A bit is securedto the bit mounting means. in one embodiment a bolt is loosely fittedinto a transverse hole formed through the mounting means, one endthereof being loosely fitted through a hole formed on one side of theconcave channel of the body. The other end of the bolt is screwed into athreaded hole formed on the other side of said concave channel. Wedgemembers are provided in concavities above the transverse channel whichare moved by bolts therethrough to wedge the mounting means downwardlywhile it is loosely held by the bolt through the transverse hole, afterwhich the bolt s tightened to secure the mounting means. In a secondembodiment the mounting means has a helical rack gear thereon meshingwith a sliding member in a transverse hole above the transverse channel,and a bolt threaded through the sliding member moves the sliding memberwhen the bolt is rotated, thereby moving the mounting means 1 Claim, 6Drawing Figures PATENTEDHAY 1 I975 '3; 730.636

' sum 1 0r 5 SUTEMARU MIZOGUCHI,

INVENTOR.

- @YMmZ-LaM ATTORNEY:

PATENTED H973 3,730,636

sum 2 or '3 SUTEMARU MIZOGUCHI,

INVENTOR.

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ATTORNEYS PATENIEU V975 3,730,636

SHEET 30F? SUTEMARU MIZOGUCHI,

INVENTOR.

Attorneys BORING HEAD This invention relates to a boring head for use ininternal cutting, and more particularly to a boring head having a bitwhich is easily extendable and retractable.

In the conventional boring head the bit is adjustably secured directlyto the boring head by means of a screw, making it necessary whenadjusting the position of the bit to loosen the screw'each time the bitis to be extended or retracted. Thus the known boring head has adisadvantage in that it requires a great deal of effort to adjust thebit thereof.

The first object of this invention is to obviate the aforementionedconstructional defect of the conventional boring head, and to provide aboring head which is simple in construction and easy to operate.

The second object of this invention is to facilitate the adjustingoperation of the bit and also facilitate the determination of the fixedbit position by improving the fixing means for fixing the bit to theboring head.

The third object of this invention is to facilitate minute adjustment ofthe bit by means of micromotion of bit mounting tables fixed to theboring head.

Those objects mentioned hereinbefore are attainable by the improvement,combination and operation of each segment constituting this invention,and the preferred embodiments thereof will be illustrated in thedetailed description set forth hereinunder with reference to theaccompanying drawings.

Amendments and modifications with regard to details of the constructionare to be included in the claims appearing hereinafter.

FIG. 1 is an elevation partially in longitudinal section, showing afirst embodiment of the boring head according to this invention.

FIG. 2 is a lateral view of the foregoing embodiment.

FIG. 3 is an bottom view of the foregoing embodiment.

FIG. 4 is an elevation partially in longitudinal section, showing asecond embodiment of this invention.

FIG. 5 is a lateral view partially in longitudinal section of theforegoing embodiment.

FIG. 6 is a cross sectional view taken on the line 66 in FIG. 5.

In the embodiment shown in FIGS. 1 to 3, the numeral 1 1 designates aboring head body having a shank 12 with a tapering, straight or anyother arbitrary shape. In the lower part of the boring head body 11 isformed a concave channel 14 traversing said body 11, the center of saidconcave channel 14 coinciding with that of the axis of the body 11, bothends of said concave channel 14 being open on the peripheral surface ofthe body 11.

A pair of bit mounting bases 15 are slidably fitted inside the concavechannel 14. On the confronting faces of these mounting bases 15 areformed traverse zigzag ridges 16 slidably engaging with each other, saidtwo mounting bases 15 with the zigzag ridges 16 engaging with each otherbeing fitted into the concave channel 14 so as to be smoothly slidablebetween both lateral sides of said channel 14.

In each of the mounting bases 15 is formed a transverse hole, a fixingbolt 18 attached to the body 11 being loosely fitted in said transversehole 17. This bolt 18 is loosely fitted in a hole 19 which is so formedon both sides of the concave channel 14 of the head 11 that itintersects at right angles with said concave channel 14, and is screwedinto a threaded portion 20 of hole 19 on one side of channel 14. Thehead 21 of the bolt 18 is fitted into a large-calibered bore 22 on theoutside end of the penetrable hole 19. On the outside of said head 21 isformed a polygonal bore 23 for engagement by a revolving tool.

The numeral 24 designates a pair of diametrically 0pposed concavitiesformed in the upper part of both ends of the concave channel 14, thelower parts of the concavities 24 communicating with the concave channel14, the upper faces 25 of said concavities 24 being inclined downwardlytowards the back thereof, as shown in FIG. 1.

The numeral 26 designates a wedge member fitted into each of theconcavities 24, the upper edge 27 of said wedge member 26 being soinclined so that it fits against the upper face 25 of each concavity 24,the underside 28 thereof being horizontal so as to fit against the upperface of each bit mounting base 15. Moreover, said underside 28 ispositioned so that part of it will extend over the upper face of eachmounting base 15, as shown in FIG. 2.

The numeral 29 designates a bolt which is loosely fitted into a hole 30provided in each wedge member 26, said bolt 29 being screwed into athreaded hole 31 provided at the back of the concavity 24, the head 32of each bolt 29 being loosely fitted inside a largecalibered bore 33formed on the outside end of the bore 30. The parts are so arranged thatsaid head 32 will be pressed against the bottom of the largecaliberedbore 33 through a washer 34. A coil spring 36 is fitted between alargecalibered bore 35 formed on the inside end of the hole 30 and theback of the concavity 24, said coil spring 36 being externally fittedaround the bolt 29, the outer end of the spring 36 being pressed againstthe bottom of the large-calibered bore 35 through a washer 36.Furthermore, in the aforementioned head 32 is formed a polygonalconcavity 37 for engagement with a revolving tool as shown in FIG. 2.The numeral 38 designates a bit secured by a bolt 39 in a concavity 42at the opposite ends of the mounting bases 15.

The numeral 40 designates scales provided on the underside of the body11, said scales 40 being formed along both sides of the concave channel14 to show the position of an indicator 41 provided on the lateral sideof each bit mounting base 15.

In the first embodiment of this invention, each bit mounting base 15 isfreely slidable inside the concave channel 14 when the bolt 18 isloosened, and the amount each bit 38 extends beyond the lateral side ofthe body 11 is freely adjustable by sliding traversely each mountingbase 15 along the zigzag ridges 14 inside the concave channel 14, theposition of each bit 38 being accurately determinable by setting theindicator on the mounting base 15 on the scale 40.

If the wedge member 26 is moved toward the back of the concavity 24 byscrewing each bolt 29 inwardly, when the bit mounting bases 15 have beenstabilized by gently tightening the bolt 18, the upper faces of themounting bases are contacted by the undersides 28 of the wedge members26 and the inclined upper edge 27 of the wedge member 26 slidesobliquely downwardly along the inclined upper face 25 of the concavity24, as

a result of which the lower part of each wedge member 26 graduallypresses each mounting base downwardly, thereby making possible minuteadjustment of the amount of the downward extension of the bit 38.

Both bit mounting bases 15 are tightly engaged at both sides of theconcave channel 14 when the bolt 18 is tightened after adjustment of theposition of said bases 15 as described hereinbefore. In this state, theboring head body 11 is attached to the main shaft of a taper shankboring machine for the boring operation.

FIGS. 4 to 6 show that the transverse minute adjustment of the bit iseasily carried out in the second embodiment of this invention.

In FIGS. 4 to 6, the numeral 5] designates a boring head body havingthereon shank 52 with a tapering, straight, or any other arbitraryshape, a dovetail channel 53 being transversely formed in the lower partof the body 51. The numeral 54 designates a bit mounting base having adovetail protrusion 55 integrally formed on the upper part thereof whichis slidably fitted into the aforementioned dovetail channel 53, ahelical rack gear 56 being formed on said protrusion 55.

In the body 51 is formed a transverse hole 57 positioned above thedovetail channel 53 and crossing said channel at right angles thereto,the central lower part of the transverse hole 57 communicating with thecentral part of the dovetail channel 53. Inside the transverse hole 57is slidably fitted a sliding element 58, a key 60 axially provided onthe upper side of the transverse hole 57 being slidably fitted into akey groove 59 on the upper side of the sliding element 58, so that saidsliding element 58 can accurately move along the axial line of thetransverse hole 57. Furthermore, on the underside of the sliding element58 is formed a helical rack gear 61 in mesh with the helical rack gear56.

The head 64 ofa bolt 63 is rotatably fitted into an annular member 62secured over one end of the transverse hole 57, a polygonal concavity 67for engagement with a revolving tool being formed on the outside of saidhead 64. The bolt 63 is concentric with the transverse hole 57 andscrewed into a threaded hole 65 formed in the sliding element 58. Alarge-calibered bore 66 is formed in the transverse hole on the end overwhich the annular member 62 is secured, and a flange 68 concentricallyformed at the base of the head 64 of the bolt 63 being supported on theinner and of the large-calibered bore 66 through washers 69 and 70. Theother end of the transverse hole 57 is closed by a lid 71 thereover.

The numeral 72 designates a bit fixed to the external end of a bolt 73,said bolt 73 being screwed into a threaded hole 74 formed obliquely inthe lower part of one end of the bit mounting base 54 and secured inposition with a setscrew 75.

In the second embodiment, as indicated in the drawings, if the bolt 63is revolved by engaging a revolving tool in the concavity 67 of the bolt63 with the helical rack gear 56 and the helical rack gear 61 of thesliding element 58 meshing with each other, then ing base 54 having theprotrusion 55 which engages with the sliding element 58 moves along thedovetail channel 53 thereb altering the amount of lateral extension ofthe bit 7 Since t e transversal movement of the mounting base 54 isextremely small as compared with the amount of rotation of the bolt 63,the amount the bit 72 extends can be very finely adjusted. If the bolt63 is revolved in the same direction continuously, the sliding element58 is ultimately brought into contact with the lid 71 as shown by thebroken line (a) in FIG. 5, the helical rack gear of the sliding element58 being completely disengaged from the helical rack gear 56 on theprotrusion 55.

In this condition, the bit mounting base 54 becomes slidableindependently of the bolt 63, thereby making it possible to move themounting base 54 to a large distance.

After the position of the bit 72 has been changed to a large extent bydisengaging the helical rack gear 61 from the helical rack gear 56 asdescribed hereinbefore, minute adjustment can again be carried out byrevolving the bolt 63, thereby moving the sliding element 58 toward theprotrusion 55 so that the rack gears 61 and 56 can mesh with each other.Therefore, in this embodiment, both minute adjustment and large-scalemovement of the position of the bit are possible.

I claim:

1. A boring head comprising a body having a shank thereon and atransverse channel in the lower part thereof and a transverse holetherein above and at right angles to said transverse channel andcommunicating with said transverse channel, a bit mounting member, aprojection provided on the upper part thereof slidably fitted into saidtransverse channel and having a helical rack gear having a plurality ofteeth on the upper surface thereof, a sliding element slidably andnonrotatably fitted into said transverse hole and having a helical rackgear having a plurality of teeth on the lower surface thereof meshingwith the helical rack gear on said projection, said sliding elementhaving a threaded hole therethrough in the direction of the axis of saidtransverse hole, and a bolt rotatably and axially immovably mounted insaid transverse hole and engageable in said threaded hole in saidsliding element, said transverse hole extending beyond said transversechannel in at least one direction thereof to accommodate the entire saidsliding element therein with the rack gears disengaged, and said boltextending at least part way into the portion of the transverse holebeyond said transverse channel, whereby rotation of said bolt moves saidsliding element along said transverse hole and the movement of saidsliding element moves said bit mounting member along said transversechannel, and said sliding element can be moved into the portion of saidtransverse hole beyond said transverse channel out of engagement withsaid bit mounting member and said bit mounting member can be freelyadjusted.

1. A boring head comprising a body having a shank thereon and atransverse channel in the lower part thereof and a transverse holetherein above and at right angles to said transverse channel andcommunicating with said transverse channel, a bit mounting member, aprojection provided on the upper part thereof slidably fitted into saidtransverse channel and having a helical rack gear having a plurality ofteeth on the upper surface thereof, a sliding element slidably andnon-rotatably fitted into said transverse hole and having a helical rackgear having a plurality of teeth on the lower surface thereof meshingwith the helical rack gear on said projection, said sliding elementhaving a threaded hole therethrough in the direction of the axis of saidtransverse hole, and a bolt rotatably and axially immovably mounted insaid transverse hole and engageable in said threaded hole in saidsliding element, said transverse hole extending beyond said transversechannel in at least one direction thereof to accommodate the entire saidsliding element therein with the rack gears disengaged, and said boltextending at least part way into the portion of the transverse holebeyond said transverse channel, whereby rotation of said bolt moves saidsliding element along said transverse hole and the movement of saidsliding element moves said bit mounting member along said transversechannel, and said sliding element can be moved into the portion of saidtransverse hole beyond said transverse channel out of engagement withsaid bit mounting member and said bit mounting member can be freelyadjusted.